Recently, instead of a code or a password that is a combination of characters and symbols, biometric authentication technologies that execute authentication using the physical characteristics of a subject person are actively researched and developed. It is typical that biometric authentication uses physical characteristics which are not consistent one another among individuals, such as a fingerprint, a venous pattern on the back of a hand, an iris pattern of an eye, and a voiceprint. In particular, authentication apparatuses using a fingerprint and a venous pattern on the back of a hand have the authentication precision improved, and are built in various devices, such as an ATM (Automatic Teller Machine) and a personal computer (PC) together with the advancement of the cost-down of the authentication apparatuses.
According to the authentication using a fingerprint and a venous pattern on the back of a hand, however, it is necessary for a subject person to contact a part of the body like a finger and a hand to the apparatus or to put those close to the apparatus. Hence, in recent days, biometric authentication technologies using an iris pattern of an eye are getting attention (see, for example, Patent Literature 1).